Category: Fiber Transceivers

Fiber optic connectors have traditionally been the biggest concern in using fiber optic systems. While connectors were once unwiedy and difficult to use, connector manufacturers have standardized and simplified connectors greatly. This increases the user use convenient increase in the use of optical fiber systems; It is also emphasising taken proper care of and deal with the optical connector. This article covers connector basics including the parts of a fiber optic connector, installing fiber optic connectors, and the cleaning and handling of installed connectors. For information on connector loss, see Connector Loss Test Measurement. Optical fiber to fiber optic interconnection can be made by a joint, a permanent connection, or a connector, and is different from the plug in it can be to disconnect and reconnect. Fiber optic connector types are as various as the applications for which they were developed. Different connector types have different characteristics, different advantages and disadvantages, and different performance parameters. But all connectors have the same four basic components.

The Ferrule: The fiber is installed in a long, thin cylinder, the ferrule, which act as a fiber alignment mechanism. The ferrule is bored through the center at a diameter that is slightly larger than the diameter of the fiber cladding. The end of the fiber is located at the end of the ferrule. Ferrules are typically made of metal or ceramic, but they may also be constructed of plastic.

The Connector Body: Also known as the connector housing, the body holds the ferrule. It is usually constructed of metal or plastic and includes one or more assembled pieces which hold the fiber in place. The details of these connector body assemblies vary among connectors, but the welding and/or crimping is commonly used to attach strength members and cable jackets to the connector body. The ferrule extends past the connector body to slip into the couping device.

The Cable: The cable is attached to the connector body. It acts as the point of entry for the fiber. Often, a strain relief boot is added over the junctioni between the cable and the connector body, providing extra stength to the junction.

The Coupling Device: Most fiber optic connectors do not use the male-female configuration common to electronic connectors. Instead, a coupling device such as an alignment sleeve is used to mate the connectors. Similar devices may be installed in fiber optic transmitters and receivers to allow these devices to be mated via a connector. These devices are also known as feed-through bulkhead adapters.

Cleaving Cleaving involves cutting the fiber end flush with the end of the ferrule. Cleaving, also called the scrible-and-break method of fiber end face preparation, takes some skill to achieve optimum results. Properly handled, the cleave produces a perpendicular, mirror-like finish. Incorrect cracks will cause the lips and the comb as shown in Figure 2. While cleaving may be done by hand, a cleaver tool, available from such manufacturers as Fujikura and FiberStore, allows for a more consistent finish and reduces the overall skill required. The steps listed below outline one procedure for producing good, consistent cleaves such as the one shown in Figure 3. 1. Place the blade of the cleaver tool at the tip of the ferrule. 2. Gently score the fiber across the cladding region in one direction. If the scoring is not done lightly, the fiber may break, making it necessary to reterminate the fiber. 3. Pull the excess, cleaved fiber up and away from the ferrule. 4. Carefully dress the nub of the fiber with a piece of 12-micron alumina-oxide paper. 5. Do the final polishing.

The use of index-matching gel, a gelatinous substance that has a refractive index close to that of the optical fiber, is a point of contention between connector manufacturers. Glycerin, available in any drug store, is a low-cost, effective index-matching gel. Using glycerin will reduce connector loss and back reflection, often dramatically. However, the index-matching gel may collect dust or abrasives that can damage the fiber end faces. It may also leak out over time, causing backreflections to increase.

Fiber optic connector is used for the connection of optical fibers or fiber optic cables. The Optical Connector provide a mechanical connection for the two fiber cables and align both cores precisely.

There have been over 100 connectors developed over the years, but a select few have stood the test of time and beat out their competition. Fiber Optic Connectors according to the different transmission media can be divided into common silicon-based optical fiber single-mode and multimode connectors, as well as other issues such as plastic and as the transmission medium of optical fiber connector; connector structure can be divided into: FC SC, ST, LC, D4, DIN, MU, the MT and so on in various forms, but SC and LC connectors are the most common types of connectors on the market. ST connector is the most popular connector for multimode networks. Different connectors are required for multimode and single-mode fibers.

In addition to connectors that tie two fiber-optic lines together, there are also Metal Adapter Panel (or fiber adapter plates) that can be used to connect multiple fiber-optic lineself. It enables you to make quick and easy fiber patch panel connections as they can snap into the enclosures easily. In a device such as this, connections can be made between any of the lines plugged into the panel. Though a single adapter panel can usually only hold a dozen or so cables, the panels can also be spliced together, allowing hundreds or thousands of connections to be made.

Specify optical fiber adapter plates for ST-, FC-, SC-, MT-RJ- or LC-type connections. Adapter plates are compatible with all wall and rack mount optical fiber enclosures and available in 6 simplex and duplex, 8 simplex and duplex and 6 quad configurations with fiber counts of up to 24 per adapter plate. They mount easily by means of plunger locks (“pushpins”). ST, FC, SC and LC connec-tor plates can be equipped with 62.5-μm and 50-μm adapters suitable for multimode applications or a sisingle modenly version is available with adapters outfitted with zirconia ceramic sleeves. Our SC and LC 10G multimode laser optimized adapter uses zirconia ceramic sleeves.

Series Features

Available in 6-, 8-, and 12-port fiber configurations,

Panel options available include ST, SC, LC and others,

High density applications can be reached through Dual and Quad LC applications,

Composite, Metal, or Ceramic sleeve options available,

Blank panels are available for use as dust covers,

Plates are available for mounting Bezel style jacks creating a mixed media environment.

In order to customize wall mount or rack mount fiber optic enclosures, FiberStore offers a wide selection of panels with various FC Adapter including ST, SC, MTRJ and LC. All modular adapter panels are assembled with industry standard adapters. FiberStore fiber adapter panels/plates can come with various fiber adapters, such as LC/SC/ST/FC/MT-RJ, E-2000 fiber optic adapters, compatible with simplex or duplex and meet TIA/EIA-568-B.3 requirements. Our adapter plates include phosphor bronze or zirconia ceramic split sleeves to fit specific network requirements. LC and SC adapter housing colors follow the TIA/EIA-568-C.3 suggested color identification scheme. Multimedia modular panels allow customization of installation for applications requiring integration of fiber optic and copper cables. Blank fiber adapter panels reserve fiber adapter panel space for future use.

Article about how to terminate fiber optic cables with expoxy, which is the most cheap, fast and easy method among all the fiber cable termination ways. Go on read! When you have bulk fiber optic cables on hand and need to terminate it with the fiber optic connectors, there are several options for you to handle this job: Epoxy and polish, mechanical cleave and crimp, and the chemical permanent method, fusing splicing the pigtails. The aim of terminating the fiber optic cables is to provide protections for the stripped fiber end in the connector. Poor termination job will result in large optical loss, even cause damages to the connectors and adapters. Among all the method mentioned above, epoxy and polishing is the cheap, fast and easy and low optical loss, so it is welcomed by most cable installers. Follow the steps and see how to terminate fiber optic cables with the Epoxy.

First, prepare you cable by stripping the cable down to the bare fibers with a fiber stripper which you can get from FiberStore. After that, mix the epoxy resin and hardener that you have prepared ahead, and load them into a syrine( Ignore this step,if you are using a pre-loaded epoxy syringes). Now, it’s time to injuct the expoxy directly from the syringe into the connector ferrule.

Once you have prepared your connector with the epox, you re read to insert the fiber cable so that the cable is seated inside of the connector wall and the bare fiber core sticks out about a half an inch from the front of the ferrule. If your cable is jacked, you will need to use the cable crimping tool to protect the connector to the jacket and strength members of the cables. Two crimps would be necessary to finish the job properly.

The next step is curing the epoxy in the connectors. You may need to place the connected end into a curing holder first to make sure that the end of fiber will not get damaged in the process of curing. Then place the cable and curing holder into a curing oven, situate the connector to make the end is facing down, by doing which, it will ensure the epoxy does not come out of the back side of the connector and compromise the strength member of the cable. As to the curing time and the temperature,follow the instruction book of your specific epoxy.

Once the epoxy are cured sufficiently, cleave the excess fiber core with a fiber cleaver tools as close to the ferrule tips as possible while avoiding any sort of twisting motion. After that, remember to dispose the fiber clipping, which could easily end up in your skin or even in you eye or respiratory system.

After the cleaving and disposing jobs done, you are ready to move on to the next step, polishing the fiber end to a smooth finish. Get a fiber polishing machine to effectively remove any excess epoxy from the ferrule tip and buff out the imperfections on the face of the fiber. A coarse surface would cause the optical loss when the light is passing through it.

When you are satisfied with your polishing job, you are now prepared to clean the ferrule and fiber tip. With a wiper dipped in 99% reagent-grade alcohol, gently wipe the surface area of the ferrule and fiber tips, then, use another wiper to dry them. Remember, the two wiper should all be lint-free.

Now, your fiber optic cable is terminated. To measure if your job is done well or not, you can use a proper fiber inspection microscope to inspect the tip and then use an optical fiber cables tester for the loss measurement.

High density fiber optic array polishing to tightest optical specifications with fiber-end surface finish to a few manometers Ra, is now offered as a service to fiber optic array manufacturers.

For applications including: Fiber optics, fiber optic arrays, waveguides, optical switches, WSXC (Wavelength Selective Cross-connects), matrix optical switches, transparent optical cross-connect switches, precision polished NxN switches, MEMS (Micro Electromechanical Systems) devices. As a stand-alone device, fused arrays offer very high coupling efficiency, high chemical resistance and high damage threshold. Coupled to one or more other fibers, the fused arrays become highly efficient fiber beamsplitters and fiber beam combiners.

Ensuring top performance of fiber optic high density arrays, presents many challenges to manufacturers of these devices, particularly in the assembly and polishing operations. Tens, hundreds or even thousands of optical fibers must be assembled with positioning tolerances within several microns. These fibers, each consisting of a 5 to 10 micron core with cladding and coating surrounding it, must then be molded together, terminating into a planar surface. The ends of these fibers must then be polished to near perfection, with flatness within a few microns from edge to edge, and very high quality optical surface finishes to < 5 angstroms. Surface finish and flatness are critical in order to maintain signal integrity and minimize loss. Traditional optical polishing techniques cannot achieve these high-performance specifications.

After extensive R&D efforts, Valley Design has developed the process and equipment fixturing required to provide these services. Valley has closely collaborated with several customers to provide prototype to production high quality polishing of fiber optic arrays.

Application For Optical Switch Polishing

Matrix optical switches, also called NxN switches, allow any input channel to be switched to any output channel. The primary objective is to enable transparent optical cross-connects where the applied signal will remain in the optical mode, and not require optical to electronic to optical conversions. For example, 64 light beams from an 8×8 fiber optic array are intercepted by an 8×8 MEMS-based array of 64 mirrors that move in and out of the beam path. MEMS are tiny mechanical components fabricated by photolithographic technology, typically on a Silicon substrate. These are movable, and in this case, the movable components are mirrors. These fiber optic arrays need to be planarized with a desired flatness of less than 1 micron. The optical fibers themselves also tolerate no imperfections and require a surface finish of only a few nanometers. With over 25 years of polishing experience, Valley can achieve these flatness and surface finish requirements.

These are measured and documented by Valley using our in-house optical interferometers and WYKO instrumentation.

Valley also provides and processes numerous types of substrate materials used for these applications including Fused Silica, Quartz, Pyrex, Glass, GaAs, LiN, InP, Sapphire, Silicon, Ceramics and many others. Valley can lap, polish, dice and edge or angle polish these parts to your specifications. Coating and metallization services are also provided.

Even though the first use of lasers in medicine was reported by Goldman in 1962-and then in 1963 for experimental cardiovascular plaque ablation-it is the Aesthetic and Ophthalmic applications that historically pushed the use and adoption of photons in medicine. In addition to invasive and non-invasive cosmetic treatments and ophthalmic therapies, urology is another mature market today using lasers and optical fiber probes. In this market lasers and optical fibers are used in transurethral laser therapy for benign prostatic hyperplasia (BPH) and kidney stone ablation.

What are the next big emerging markets? Groups and organizations in the public and private sectors are developing systems that incorporate an optical fiber probe for diagnostic and therapeutic purposes. Many of these applications target disposable probes at high volume procedures. This creates a challenge for device manufacturers and their suppliers to produce, on a repeatable basis, an optical probe requiring crucial complex engineering and control at a price point the market (and insurance companies) can bear. In vivo probes for optical coherence tomography are already on the market. Other examples of emerging applications include: cancer detection; tumor ablation; other soft tissue ablation such as meniscuses; probes for sensing and imaging; and the incorporation of optical fiber in existing medical devices found in MRI suites, radiation suites, and X-Ray suites.

For the first time, researchers have shown that a stable frequency reference can be reliably transmitted for more than 300 kilometers over a standard fiber optic telecommunications network in order to synchronize two radio telescopes.

In The Optical Society of America’s Optica journal, researchers from a consortium of Australian institutions recently reported this successful transmission between two radio telescopes using an optical fiber link. They also demonstrated that the technique’s performance was superior to using an atomic clock at each telescope.

Stable frequency references, used to calibrate clocks and instruments that make ultra-precise measurements, are usually only available at facilities that use expensive atomic clocks to generate the references. This new technology could help scientists anywhere to access the frequency standard by simply tapping into the telecommunications network.

This new technique required no substantial changes to the rest of the fiber optic network and was easy to implement. Most impressively, the demonstration was performed over a fiber optic network that was transmitting live telecommunications traffic at the same time. By running the experiment on optical fibers carrying normal traffic, the researchers showed that transmitting the stable frequency standard did not affect the data or telephone calls on other channels.

To keep the frequency stable during transmission, the researchers sent the signal through the network to a selected destination and then reflected it back. Then, the returning signal was used to determine whether any changes occurred. After each round trip, any frequency shift was subtracted to precisely compensate for the measured changes. For every 100 kilometers of fiber, the round trip for the signal took approximately 1 millisecond.

According to the researchers, the successful demonstration shows that this new method is ready for use by radio astronomers who want to avoid using multiple atomic clocks across a telephone array. This capability would also allow any scientist with access to a telecommunications network to broadcast stable frequency references across a national fiber optic network.

The ability to send stable frequency references over a telecommunications network may be especially useful for radio telescope arrays such as the Square Kilometer Array (SKA).  SKA is a global effort to build the world’s largest telescope using arrays in Australia and South Africa. When completed, SKA will detect faint radio waves from deep space with an approximately 50 times greater sensitivity than that of the Hubble telescope. In addition, individual radio telescopes will be linked to create a total collection area of about 1 million square meters.

The research group hopes that ready access to frequency standards as stable as those in a national measurement laboratory will serve as an enabling technology for many applications that demand precise timing and accurate frequency measurements.